1. Field of the Invention
The present invention relates to a hydraulic machine of the type traversed by a main flow of water, comprising at least one blade profile of a turbine, having an upstream end and a downstream end, in the vicinity of which is formed at least one eddy zone or a reduced-pressure zone or a cavitation zone, the machine comprising means of injecting a flow tapped from said main flow, not modified relative to the main flow, in said eddy or reduced-pressure or cavitation zone so as to locally modify the main flow or increase the pressure in this zone.
2. Brief Description of the Related Art
Such a hydraulic machine is used, for example, in a plant for producing hydroelectricity. The machine is installed in the path of the current or is supplied with water from a reservoir into which one or more water courses are discharged.
In these hydraulic machines, there are zones in which the main flow traversing the machine is disturbed and forms eddies or exhibits a reduced pressure or cavitation zones, because of the configuration of the machine. Such zones disrupt the general performance of the hydraulic machine because they reduce the efficiency of action of the main flow in the hydraulic machine or cause problems of operation of the hydraulic machine.
The document U.S. Pat. No. 1,942,995 describes a hydraulic machine of the abovementioned type, making it possible to inject a flow tapped from the main flow in the cavitation zone being formed along the blades of the turbine wheel.
However, the outlet orifices for the tapped flow are arranged to inject the flow in a direction roughly perpendicular to the direction of the main flow. Such orifices do not make it possible to eliminate the eddy zones that are formed in the trail of the blades and also disturb the general performance of the hydraulic machine.